* feat(plugin): add ModelRouter before auth with single-slot routing targets ## Motivation Plugins that need to change execution based on the **original inbound request** (protocol format, raw body, headers, query, stream flag, metadata, etc.) often resorted to virtual/trampoline models or routing inside interceptors. This commit adds **ModelRouter**: a pluggable layer **before** model-to-provider resolution and AuthManager credential selection, so plugins can declare who executes a request without spoofing the client model name. This is a **new capability**, not a bugfix on the existing chain. With no ModelRouter plugins loaded, behavior matches upstream. ## Pipeline placement - `execute`, `stream`, and `count` (and image paths via AuthManager) call `applyModelRouter()` before building `coreexecutor.Request`. - Routing runs **before** the request interceptor (before auth), so routers see the client’s original context. After a plugin executor is chosen, the existing **after-auth interceptor → response/stream interceptor** chain still applies. - Internal `ExecuteModel` / `ExecuteModelStream` (host callbacks) support `SkipRouterPluginID` so nested calls do not re-enter the same router. ## Routing API (single slot, mutually exclusive) `ModelRouteResponse` uses **one target slot** to avoid ambiguity when both `TargetExecutorPluginID` and `TargetProvider` were set and the host ignored one: | Field | Meaning | |-------|---------| | `Handled` | `false`: this router declines; try the next router or default path | | `TargetKind` | `self` \| `executor` \| `provider` (pick one) | | `Target` | `self`/`executor`: plugin ID; `provider`: built-in provider key | | `TargetModel` | Optional on `provider` only; empty keeps client `RequestedModel` | | `Reason` | Optional diagnostic text | - **self**: the router plugin’s own executor (`Target` normalized to the router’s plugin ID). - **executor**: another plugin’s executor; host pre-checks with `executorPluginReady()` (executor declared and provider identifier resolvable) to avoid handled routes that 500 at execution. - **provider**: skip registry model resolution; fixed built-in AuthManager path; optional `TargetModel` for execution model only—**does not** change outward requested-model metadata. Routers run in **descending plugin priority** (tie-break: ascending plugin ID). Panic, error, invalid target, or unavailable executor/provider → log and **fall through to the next router**; if none handle, use the original provider+auth flow. ## Context exposed to routers `ModelRouteRequest` includes: - `SourceFormat`, `RequestedModel`, `Stream` - `Headers`, `Query`, `Body` (defensive copies) - `Metadata` (best-effort read-only context snapshot) - `AvailableProviders`: built-in provider keys with at least one **non-disabled** auth (`AuthManager.AvailableProviders()`). **Does not** reflect per-model cooldown or transient unavailability—treat as an optimistic snapshot. Adds `AuthManager.HasProviderAuth()` and `AvailableProviders()`, excluding `Disabled` and `StatusDisabled` auths consistently with credential selection. ## Host and RPC - Go plugins: `pluginapi.ModelRouter` + `RouteModel()`. - RPC plugins: `pluginabi.MethodModelRoute` (`model.route`), capability flag `model_router`. - `pluginhost.Host` implements `RouteModel` / `RouteModelExcept`; handlers use `SetModelRouterHost` or a `PluginHost` type assertion; **direct executor** paths use `ExecutePluginExecutor*` / `CountPluginExecutor`. - No bundled example ModelRouter plugin; capability is active only when a third-party plugin declares `model_router` and loads. ## Plugin RPC schema (policy A, upstream-aligned) - `pluginabi.SchemaVersion` stays **1**: capability additions (`model_router`, `model.route`) do not bump the number; increment only on breaking RPC JSON changes. - Host sends `schema_version` at register; reject only if the plugin declares a **higher** version than the host. - No unpublished “ModelRouter requires schema ≥ 3” gate (v3 single-slot API was never public). - Existing plugins and examples without `model_router` (`schema_version: 1`) need no changes. - RPC ModelRouter: `schema_version: 1` + `model_router: true` + implement `model.route`. ## Path consistency within this commit - Provider routes reuse image-only model checks (e.g. `gpt-image-2`) on the normalized model, same as the default AuthManager path. - `count` aligned with execute/stream: `SkipRouterPluginID`, query/headers injection, interceptor skip semantics. - Handlers: `modelRoutersEnabled` treats hosts without `HasModelRouters` as disabled (same as before ModelRouter existed); `pluginhost.Host` implements the detector. - API docs: `ModelRouter` explicitly includes built-in **provider** targets (in addition to plugin executors and the router’s own executor). ## Testing go test ./internal/pluginhost ./sdk/api/handlers ./sdk/pluginapi ./sdk/pluginabi ./sdk/cliproxy/auth go build -o test-output ./cmd/server && rm test-output go test ./... * fix(handlers): address ModelRouter review feedback - Use modelExecutionQuery for plugin executor and AuthManager paths so inbound URL query matches router/header behavior - Guard queryFromContext when gin Request.URL is nil - Read plugin executor stream chunks via nextStreamChunk to exit on cancel - Drop redundant clonePluginMetadata on capability record meta Tests cover query propagation, stream cancel, and nil URL safety. * feat(plugin): add Claude web search router example Add a Claude Code web_search ModelRouter example that can route matching Claude requests through Antigravity, Codex, xAI, or Tavily. The plugin includes executor orchestration, backend fallback/penalty handling, Tavily API key support, Claude-compatible response assembly, stream forwarding, and focused unit coverage for detection, fallback routing, model resolution, penalties, stream forwarding, and Tavily behavior. Verification: go test -count=1 ./... in examples/plugin/claude-web-search-router/go; go build -buildmode=c-shared for the plugin; go build ./cmd/server; live local CPA curl coverage for plugin load, four explicit routes, fallback, and Codex spark routing. * fix(pluginhost): validate executor routes before fallback * fix(pluginhost): skip oauth-only executor routes
Standard Dynamic Library Plugin Examples
This directory contains standard dynamic library plugin examples for the CLIProxyAPI C ABI.
Layout
simple/- : Go-only plugin resource that calls host auth file callbacks (, , , ).- : full provider-native skeleton that declares every supported capability.
model/: model capability only.auth/: auth provider capability only.frontend-auth/: frontend auth provider capability only.frontend-auth-exclusive/: frontend auth provider that becomes the only request authentication provider when selected.executor/: executor capability only.protocol-format/: minimal executor focused on input/output format declarations.request-translator/: request translation capability only.request-normalizer/: request normalization capability only.codex-service-tier/: Go-only request normalizer that sets Codexgpt-5.5requests to the priority service tier when enabled.scheduler/: Go-only scheduler that can select a configured auth ID, delegate to a built-in scheduler, or deny picks.claude-web-search-router/: ModelRouter + executor for Claude Code built-inweb_search(antigravity / codex / xai / Tavily). Seeclaude-web-search-router/README.md.response-translator/: response translation capability only.response-normalizer/: response normalization capability only.thinking/: thinking applier capability only.usage/: usage observer capability only.cli/: command-line capability only.management-api/: Management API and resource capability only.host-callback/: minimal plugin resource that demonstrates host callbacks.host-callback-auth-files/: Go-only plugin resource that calls host auth file callbacks.host-model-callback/: Go-only plugin resource that calls the host model execution callbacks.
Most standard capability examples contain go/, c/, and rust/ subdirectories. Specialized examples may provide only the implementation language they need.
Codex Service Tier
codex-service-tier declares the request normalization capability. When fast is true, it sets service_tier to priority for requests where req.ToFormat is codex and req.Model is gpt-5.5.
plugins:
configs:
codex-service-tier:
enabled: true
priority: 1
fast: false
Host Auth Files Callback
host-callback-auth-files declares the Management API capability and exposes a browser resource named Host Auth Files. The resource demonstrates host.auth.list, host.auth.get (physical JSON file), host.auth.get_runtime, and host.auth.save.
plugins:
configs:
host-callback-auth-files:
enabled: true
priority: 1
See host-callback-auth-files/README.md for URL examples.
Host Model Callback
host-model-callback declares the Management API capability and exposes a browser resource named Host Model Callback. The resource calls host.model.execute for non-streaming requests and host.model.execute_stream plus host.model.stream_read for streaming requests. It demonstrates explicit stream close with host.model.stream_close and an implicit_close=true option for RPC-scope host cleanup.
When the resource forwards its host_callback_id, CPA identifies the plugin that initiated the host model callback and skips that same plugin's interceptors for the nested execution. This makes host model callbacks non-recursive for the caller while allowing other plugins to intercept the nested request.
plugins:
configs:
host-model-callback:
enabled: true
priority: 1
The default example model is gpt-5.5, but the request succeeds only when the current CPA model and auth configuration can route that model.
Scheduler
scheduler declares the scheduler capability. It can select a configured auth ID from the candidate list, delegate to the built-in fill-first or round-robin scheduler, or reject picks when deny is true.
plugins:
configs:
scheduler:
enabled: true
priority: 1
auth_id: ""
delegate: ""
deny: false
auth_id selects a matching candidate when delegate is empty. delegate accepts "", fill-first, or round-robin; other non-empty values leave the pick unhandled. deny returns a scheduler error.
Build All Examples
make -C examples/plugin list
make -C examples/plugin build
Artifacts are written to examples/plugin/bin.
Notes
protocol-format uses a minimal executor because format declarations belong to executor capabilities.
host-callback uses a minimal plugin resource because host callbacks are invoked from plugin methods and are not standalone capabilities.
Menu resources returned by management.register through the resources field are exposed by CPA under /v0/resource/plugins/<pluginID>/.... Authenticated plugin Management API routes remain under /v0/management/....